How to change the transparent content background to white?

To make the background of your content white, you can add this line to your style.css:

#content{ background-color: #FFF; }

The blog title is wrong. You can check for this at the Reading section under Setting inside WP-Admin. You might pick the wrong post page for the blog.

Install this Custom CSS Manager plugin and use its section of the dashboard to hold your CSS modifications, including this code:

#main {
 overflow: hidden;
}